It's just like davyk says.
I've never had experience of the tyre magic product that you mentioned but to be honest I'm not so sure I would want to be driving around long term on a Tyre Magic fix. I'd still get it fixed properly or replaced should a puncture occur.
Daily F20 125d | Alpine white | coral red leather | visibility pack | driver comfort pack | Business pro | black panel display | heated seats | BMW P Black grill
Project Peugeot 205 1.6 GTi | Alpine white | No ABS | No traction control | No power steering... pretty much just a car